"I deeply regret that my pursuit of an activity I love and practice responsibly and legally resulted in the taking of this lion. That was never my intention," the letter read. "I apologize profoundly for this inconvenience and promise you that we will do our best to resume normal operations as soon as possible."

In the letter, Palmer notes that he does not discuss hunting with his patients because he understands "it can be a divisive and emotionally charged topic." However, the dentist maintains that "to my knowledge, everything about this trip was legal and properly handled and conducted."

"I had no idea that the lion I took was a known, local favorite, was collared and part of a study until the end of the hunt," said Palmer. "I relied on the expertise of my local professional guides to ensure a legal hunt. I have not been contacted by authorities in Zimbabwe or in the U.S. about this situation, but will assist them in any inquiries they may have."

The killing of Cecil has outraged many people, and caused Palmer's dental practice's social media presence to go offline. Late night host Jimmy Kimmel became choked up on Tuesday's Jimmy Kimmel Live! while addressing the incident.